With his decision made, Seimei didn't waste any more time. He exited Sage Mode, packed up his belongings, and used Flying Thunder God Jutsu to teleport back to Moon Island.
Near his cabin, he quickly rinsed off in the nearby stream before heading inside, collapsing onto his bed, and falling asleep.
The night passed without a word.
---
The next day, bright and early, Seimei was up.
After a quick wash and some stretches, he dove into training.
He had to admit, Sage Mode at lv9, with its qualitative leap, gave a massive boost to his physical enhancement training.
In just one hour, he could feel clear, tangible progress.
Seimei could tell—his body's transformation was going to happen much sooner than expected.
Filled with anticipation, he threw himself into round after round of training.
Before he knew it, evening rolled around.
Normally, per his schedule, he'd pause Body of the Extreme training at this point and switch to Reflection Heart Jutsu to push his Sharingan's evolution.
But today, Seimei kept going. He recalled his shadow clones, spent about fifteen minutes absorbing and processing their training experience and memories, then jumped right back into the same training routine he'd been grinding for the past ten-plus hours.
This went on for another six hours, deep into the night.
Finally, after completing another round of Body of the Extreme, Seimei exited Sage Mode, halting his physical enhancement training.
Locking onto the Flying Thunder God mark on Moon Island, he teleported outside.
Inhale… Exhale…
Breathing in the fresh air, Seimei felt his exhausted spirit lighten just a bit.
After a few seconds, waiting for the burns from the volcano's heat to heal, he dispelled the Multiple Shadow Clone Jutsu with a thought.
In an instant, every shadow clone—inside and outside the island—dissolved.
A flood of memories surged into his mind, making his brow furrow.
Pushing through the discomfort, he set the memories aside for now. He first sorted and stored the chakra and natural energy that came with them, then began sifting through the memories.
It took about fifteen minutes to fully process the training experience within them.
Opening his eyes and taking a moment to collect himself, Seimei started reviewing the results of today's tests.
First up: the cost of practicing Sage Mode.
After this level-up, he could maintain Sage Mode longer and with better stability, increasing his proficiency gains per hour.
Over the course of a day, his proficiency points from Sage Mode jumped from 3,500 to 4,000—a 500-point increase.
But the real surprise was the chakra and natural energy consumption. Just like when he went from lv7 to lv8, it had decreased.
And not just by a little.
Thanks to the qualitative leap from this level-up, practicing Sage Mode now cost an average of 700 chakra and natural energy points per proficiency point.
That meant a full day's training consumed about 2.8 million points—down from 4 million, a savings of 1.2 million points.
Seimei was thrilled.
Those 1.2 million points, combined with the 600,000-point reduction in physical enhancement costs from Sage Mode's lv8 upgrade and the 500,000-point reduction in Sage Mode training costs, totaled a savings of 2.3 million points.
Originally, his daily chakra deficit was 4.18 million points. After this 2.3 million reduction, it dropped to 1.88 million.
Clearly, that wasn't a huge burden anymore.
But that wasn't the full picture.
Unlike the reduced cost of Sage Mode training, his physical enhancement costs had gone up—and significantly.
It wasn't that Sage Mode's boost had weakened. In fact, the chakra cost for that specific part had dropped considerably.
The issue was reallocating the six hours he'd been spending on Reflection Heart Jutsu to stimulate his Sharingan's evolution to Body of the Extreme instead.
This extended his physical enhancement training by nearly half.
Naturally, his chakra and natural energy consumption scaled up proportionally.
Before today, he was investing about 27 million points daily into physical enhancement.
By that ratio, it should now require around 40 million points.
No doubt, that'd be a massive burden.
Thankfully, Sage Mode's lv9 upgrade meant the extra chakra and natural energy needed for its boost had decreased significantly.
So, all things considered, he was looking at about 35 million points for physical enhancement—only 8 million more than before.
While that wasn't a small number, the 3 million points saved from pausing Reflection Heart Jutsu and the 1.2 million saved from Sage Mode's reduced costs helped offset it.
With his current chakra reserves, an extra daily deficit of 3.8 million points (8 million - 3 million - 1.2 million) was manageable in the short term.
And short-term was all he needed.
With such a big spike in consumption, the results for his physical enhancement were, unsurprisingly, impressive.
Based on today's progress, Seimei estimated his body would hit the transformation threshold by mid-November—just a month away.
That was nearly a month earlier than his previous estimate of mid-December.
This leap came from both extending Body of the Extreme training time and leveraging the boosted effects of lv9 Sage Mode.
Only by combining the two could he achieve such a dramatic improvement.
That one-month window would also be enough to push Sage Mode to lv10 (0/0)—its perfected state.
At that point, not only would Sage Mode training stop costing chakra and natural energy, but the cost of using it to enhance Body of the Extreme would drop too.
Plus, a month from now, with his body transformed and his Sharingan ready to progress further, he could return those six hours to Reflection Heart Jutsu, shortening Body of the Extreme training and further reducing chakra costs.
That's why Seimei was confident he only needed enough chakra reserves for the short term.
With these thoughts flashing through his mind, he let them settle and headed to the stream by his cabin. After washing his face, he dragged his exhausted body inside to rest.
Seimei figured he'd sleep straight through to morning. But in the dead of night, an unexpected message jolted him awake.